Organic electroluminescent device, method of manufacturing the same, and electronic apparatus

ABSTRACT

An organic electroluminescent device comprising: an organic thin-film transistor element including at least an active layer made of an organic material; and an organic electroluminescent element driven by the organic thin-film transistor element.

TECHNICAL FIELD

[0001] The present invention relates to an organic electroluminescentdevice, a method of manufacturing the same, and an electronic apparatus.More specifically, the invention relates to an organicelectroluminescent device for displaying various information, a methodof manufacturing the same, and an electronic apparatus.

BACKGROUND OF THE INVENTION

[0002] Thin film transistors (TFTs) are mainly used for driving pixelsof flat-panel-displays typified by liquid-crystal displays, or organicelectroluminescent displays. Known thin-film transistors have an activelayer comprising an inorganic semiconductor such as silicon or the like.

[0003] Since known inorganic semiconductor-thin-film transistors have alittle flexibility, it has been difficult to obtain a display in adesired shape. Further, forming known thin-film transistors requirecomplex processes and sophisticated equipment such as high-vacuumequipment.

[0004] Subsequently, a first object of the present invention is toprovide an organic electroluminescent device which is driven by athin-film transistor using a flexible organic-semiconductive material,and an electronic apparatus. The second object is to provide a method ofmanufacturing a thin-film transistor and an organic electroluminescentelement using a simple method, such as a liquid-phase process.

SUMMARY OF THE INVENTION

[0005] An organic electroluminescent device according to the presentinvention comprises an organic thin-film transistor element including atleast an active layer made from an organic-material, and an organicelectroluminescent element driven by the organic thin-film transistor.As the organic thin-film transistor is adopted for driving the organicelectroluminescent element, the entire manufacturing operation may beperformed by inkjet processes without using special equipments.Accordingly, the manufacturing cost can be reduced.

[0006] The organic electroluminescent device may further comprise asubstrate, and the organic electroluminescent element may be providedbetween the substrate and the organic thin-film transistor element.Otherwise, the organic thin-film transistor element may be providedbetween the substrate and the organic electroluminescent element. Ineither configuration, the substrate, the organic electroluminescentelement, and the organic thin-film transistor element do not contacteach other.

[0007] It is arranged that the area obtained by adding the area of asource region to the area of a drain region of the organic thin-filmtransistor element becomes larger than an area of a region (e.g.,luminescent layer 13 in FIG. 5) in which a luminescent material isplaced. The source and the drain, which form the organic thin-filmtransistor element, are configured to have bent parts that face eachother at a predetermined spacing. A gate is provided covering the bentparts of the source and the drain. According to the above-describedconfiguration, the width of the gate becomes longer, and the organicthin-film transistor element becomes adequate for driving the organicelectroluminescent element. The bent parts of the source and the drainmay be formed in a comb-shape, or a spiral-shape, facing each other at apredetermined spacing.

[0008] A method of manufacturing an organic electroluminescent deviceaccording to the present invention, comprises a step of forming anorganic electroluminescent element for performing predetermined displayabove a substrate, and a step of forming an organic thin-film transistorelement, which drives the organic electroluminescent element, above theorganic electroluminescent element.

[0009] A method of manufacturing another organic electroluminescentdevice according to the present invention, comprises a step of formingan organic thin-film transistor element above a substrate, and a step offorming an organic electroluminescent element which is driven by theorganic thin-film transistor element and performs a predetermineddisplay, above the organic thin-film transistor element.

[0010] In either case, for performing the display, it is arranged thatthe area per pixel obtained by adding the area of a source region to thearea of a drain region of the organic thin-film transistor element, islarger than the area of a region in which a luminescent material isdisposed. The source and the drain, which form the organic thin-filmtransistor element, have bent parts that face each other at apredetermined spacing. A gate is provided covering the bent parts of thesource and the drain. According to the configuration, the width of thegate becomes longer, and the organic thin-film transistor elementbecomes adequate for driving the organic electroluminescent element. Thebent parts of the source and the drain are provided in a comb-shape, ora spiral-shape, facing each other at a predetermined spacing.

[0011] Further, at least the organic thin-film transistor and an organicluminescent layer of the organic electroluminescent element are formedby liquid-phase processes. Thus, the organic electroluminescent devicecan be manufactured without using a high-vacuum chamber. That is to say,the high-vacuum chamber can become unnecessary when the organicthin-film transistor and the organic-luminescent layer of the organicelectroluminescent element are formed by the known liquid-phaseprocesses, such as an inkjet method, spin coating, dipping, and soforth. Accordingly, the manufacturing cost is lowered.

[0012] In short, according to the configuration in which the organicthin-film transistor is adopted for driving the organicelectroluminescent element, the organic electroluminescent device may bemanufactured by the liquid-phase processes such as an inkjet processwithout using special devices without using special equipments.

[0013] An electronic apparatus according to the present inventioncomprises the organic electroluminescent device according to the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a sectional view showing the configuration of a firstembodiment of an organic electroluminescent device according to thepresent invention.

[0015]FIG. 2 is a sectional view showing the configuration of a secondembodiment of an organic electroluminescent device according to thepresent invention.

[0016]FIG. 3 shows a first process for manufacturing the organicelectroluminescent device according to the first embodiment of thepresent invention, wherein part (a) is a plan view and part (b) is asectional view.

[0017]FIG. 4 shows a second process for manufacturing the organicelectroluminescent device according to the first embodiment of thepresent invention, wherein part (a) is a plan view and part (b) is asectional view.

[0018]FIG. 5 shows a third process for manufacturing the organicelectroluminescent device according to the first embodiment of thepresent invention, wherein part (a) is a plan view and part (b) is asectional view.

[0019]FIG. 6 shows a fourth process for manufacturing the organicelectroluminescent device according to the first embodiment of thepresent invention, wherein part (a) is a plan view and part (b) is asectional view.

[0020]FIG. 7 shows a fifth process for manufacturing the organicelectroluminescent device according to the first embodiment of thepresent invention, wherein part (a) is a plan view and part (b) is asectional view.

[0021]FIG. 8 shows a sixth process for manufacturing the organicelectroluminescent device according to the first embodiment of thepresent invention, wherein part (a) is a plan view and part (b) is asectional view.

[0022]FIG. 9 is a view showing a first step of procedures for forming avia hole.

[0023]FIG. 10 is a view showing a second step of the procedures forforming the via hole.

[0024]FIG. 11 is a view showing a third step of the procedures forforming the via hole.

[0025]FIG. 12 is a view showing a fourth step of the procedures forforming the via hole.

[0026]FIG. 13 is a view showing a fifth step of the procedures forforming the via hole.

[0027]FIG. 14 is a view showing a seventh process for manufacturing theorganic electroluminescent device according to the first embodiment ofthe present invention, wherein part (a) is a plan view and part (b) is asectional view.

[0028]FIG. 15 is a view showing an eighth process for manufacturing theorganic electroluminescent device according to the first embodiment ofthe present invention, wherein part (a) is a plan view and part (b) is asectional view.

[0029]FIG. 16 is a view showing a ninth process for manufacturing theorganic electroluminescent device according to the first embodiment ofthe present invention, wherein part (a) is a plan view and part (b) is asectional view.

[0030]FIG. 17 is a view showing a tenth process for manufacturing theorganic electroluminescent device according to the first embodiment ofthe present invention, wherein part (a) is a plan view and part (b) is asectional view.

[0031]FIG. 18 is a view showing an eleventh process for manufacturingthe organic electroluminescent device according to the first embodimentof the present invention, wherein part (a) is a plan view and part (b)is a sectional view.

[0032]FIG. 19 is a view showing a twelfth process for manufacturing theorganic electroluminescent device according to the first embodiment ofthe present invention, wherein part (a) is a plan view and part (b) is asectional view.

[0033]FIG. 20 is a view showing a first process for manufacturing anorganic electroluminescent device according to a second embodiment ofthe present invention, wherein part (a) is a plan view and part (b) is asectional view.

[0034]FIG. 21 is a view showing a second process for manufacturing theorganic electroluminescent device according to the second embodiment ofthe present invention, wherein part (a) is a plan view and part (b) is asectional view.

[0035]FIG. 22 is a view showing a third process for manufacturing theorganic electroluminescent device according to the second embodiment ofthe present invention, wherein part (a) is a plan view and part (b) is asectional view.

[0036]FIG. 23 is a view showing a fourth process for manufacturing theorganic electroluminescent device according to the second embodiment ofthe present invention, wherein part (a) is a plan view and part (b) is asectional view.

[0037]FIG. 24 is a view showing a fifth process for manufacturing theorganic electroluminescent device according to the second embodiment ofthe present invention, wherein part (a) is a plan view and part (b) is asectional view.

[0038]FIG. 25 is a view showing a sixth process for manufacturing theorganic electroluminescent device according to the second embodiment ofthe present invention, wherein part (a) is a plan view and part (b) is asectional view.

[0039]FIG. 26 is a view showing a seventh process for manufacturing theorganic electroluminescent device according to the second embodiment ofthe present invention, wherein part (a) is a plan view and part (b) is asectional view.

[0040]FIG. 27 is a view showing an eighth process for manufacturing theorganic electroluminescent device according to the second embodiment ofthe present invention, wherein part (a) is a plan view and part (b) is asectional view.

[0041]FIG. 28 is a view showing a ninth process for manufacturing theorganic electroluminescent device according to the second embodiment ofthe present invention, wherein part (a) is a plan view and part (b) is asectional view.

[0042]FIG. 29 is a view showing an example in which an organicelectroluminescent device having an electronic circuit of an embodimentof the present invention is applied to a mobile personal computer.

[0043]FIG. 30 is a view showing an example of a mobile phone to which anorganic electroluminescent device having an_electronic circuit of thepresent invention is applied for the display unit thereof.

[0044]FIG. 31 is a view showing an example of a digital-still camera towhich an organic electroluminescent device having an electronic circuitof the present invention is applied for the finder.

REFERENCE NUMERALS

[0045]10: substrate

[0046]11: transparent conductive film

[0047]12: insulating film

[0048]13: luminescent layer

[0049]14: cathode pattern

[0050]20, 20 a: interlayer-insulating film

[0051]21: via hole

[0052]22 a, 22 b: interlayer wiring

[0053]30: source

[0054]31: drain

[0055]32: semiconductor layer

[0056]33: gate line

[0057]34: gate-insulating film

[0058]35: source line

[0059]41: self-organizing film

[0060]42: photo mask

[0061]43: self-organizing-film pattern

[0062]44: interlayer-insulating-film pattern

DESCRIPTION OF THE EMBODIMENTS

[0063] The embodiments of the present invention will be described withreference to the drawings. In the following description, if a partincluded in one of the drawings is shown in another drawing, the part isdenoted by the same reference numeral.

[0064]FIG. 1 is a sectional view showing the configuration of the firstembodiment of an organic electroluminescent device according to thepresent invention, showing a part for one pixel. As shown in thisfigure, the organic electroluminescent device of this embodimentincludes a transparent conductive film 11, a luminescent layer 13, aninsulating film 12 provided around the luminescent layer 13, a cathodelayer pattern 14, an interlayer-insulating film 20, a drain 31 and asource 30 that are provided facing each other, an organic-semiconductorlayer 32, a gate insulating film 34, a gate line 33, aninterlayer-insulating film 20 a, and a source line 35 that are stackedon a transparent substrate 10 in that order. An interlayer wiring 22 aelectrically connects the drain 31 and the cathode-layer pattern 14, andan interlayer wiring 22 b electrically connects the source 30 and thesource line 35.

[0065] In the configuration shown in this figure, the transparentsubstrate 10 is used as a display surface, and the contents of thedisplay provided by the luminescent layer 13 are observed through thetransparent conductive film 11 and the transparent substrate 10. That isto say, the gate line 33, the drain 31, and the source 30, which form anorganic thin-film transistor, drive an organic electroluminescentelement including the luminescent layer 13, thereby displaying onepixel.

[0066]FIG. 2 is a sectional view showing the configuration of the secondembodiment of the organic electroluminescent device according to thepresent invention, showing the configuration of one pixel. As shown inthis figure, the organic electroluminescent device according to thisembodiment includes a source line 35, an interlayer-insulating film 20,a gate line 33, a gate-insulating film 34, an organic-semiconductorlayer 32, a drain 31 and a source 30 that are provided facing eachother, an interlayer-insulating film 20a, an interlayer wiring 22, acathode pattern 14, a luminescent layer 13, and a transparent conductivefilm 11 that are stacked on a substrate 10 in that order. An interlayerwiring 22 a electrically connects the drain 31 and the cathode-layerpattern 14, and an interlayer wiring 22 b electrically connects thesource 30 and the source line 35.

[0067] In the configuration shown in this figure, the transparentconductive film 11 is used as a display surface, and the contents of thedisplay provided by the luminescent layer 13, which is formed accordingto the shape of the cathode pattern 14, are observed through thetransparent conductive film 11. That is to say, the gate line 33, thedrain 31, and the source 30, which form an organic thin-film transistor,drive an organic electroluminescent element including the luminescentlayer 13, thereby displaying one pixel.

[0068] The steps for manufacturing the organic electroluminescent deviceaccording to the first embodiment will now be described. FIGS. 3 to 19show processes for manufacturing the organic electroluminescent device.In FIGS. 3 to 8 and 14 to 19, parts (a) are plan views, and parts (b)are sectional views through portions A-A shown in the parts (a). FIGS. 9to 13 are sectional views.

[0069] In FIG. 3, the substrate 10 is made of a transparent materialsuch as glass, quartz, or plastic (synthetic resin). It is preferablethat the transparent conductive film 11 be made of ITO (indium tinoxide). However, the transparent conductive film 11 may be made ofmaterials other than ITO film, as long as the materials are transparentand highly conductive. In this embodiment, glass and ITO is used.

[0070] In FIG. 4, the insulating film 12 is provided for preventing aleakage current between the cathode pattern 14 and the transparentconductive layer 11. In this embodiment, SiO₂ is used. Other materialsmay be used, as long as they are insulative. Polyimide resin or thelike, which is an organic material, may be used. In this embodiment,using a liquid material obtained by dissolving polysilazane in xylene asthe material, the insulating film 12 is formed by an inkjet (I/J) methodonly for areas other than a cylindrical hole that forms a luminescentarea. The polysilazane solution is applied by an I/J method, and isheated to a temperature of 250° C. for 10 minutes. Thus, an SiO₂ filmthat is 150 nm thick is formed in a desired shape.

[0071] In FIG. 5, the luminescent layer 13 may comprise two layersincluding a hole-injecting layer for injecting a hole and alight-emitting organic electroluminescent layer. Both the materials areformed by an I/J method, but may be formed by spin coating, vapordeposition, and so forth.

[0072] The luminescent layer 13 is formed in the cylindrical hole of theinsulating film 12. In this embodiment, only the organicelectroluminescent layer is formed by an I/J method. The luminescentlayer 13 is formed by applying a liquid material that is a solution inwhich a polyfluorene polymer is dissolved in a xylene solvent, using anI/J method, and by drying and removing the solvent. The luminescentlayer 13 is about 80 nm thick. For the organic electroluminescent layer,an organic electroluminescent material such as polyparaphenylenevinylene (PPV) may be used.

[0073] In FIG. 6, the cathode-layer pattern 14 is made of metal. Usingmaterials such as gold, silver, copper and so forth, the cathode-layerpattern 14 is formed by patterning using an I/J method. Other metal suchas aluminum may be formed by a method such as vapor deposition. In thisembodiment, a solution in which gold complex is dissolved in an ethanolsolution is used. As the gold complex, a material denoted by(CH₃)₃—P—Au—CH₃ is used. The concentration of the material is 2 percentby weight. The solution is applied by an I/J method,and is heated to atemperature of 80° C. Thus, a gold-film pattern which is 50 nm thick,and exhibits good conductivity is obtained.

[0074] Next, as shown in FIG. 7, the interlayer-insulating film 20 isformed. For the interlayer-insulating film 20, a polymeric material suchas polyvinyl alcohol (PVA) or polyimide is used. An inorganic materialsuch as SiO₂ may be used. When the polymeric material is used, a film isformed by spin coating, an I/J method, and so forth. In this embodiment,PVA water solution is spin coated for forming a PVA film having athickness of 1.5 μm.

[0075] A via hole 21 a for performing interlayer wiring is formed asshown in FIG. 8. The details of processes for forming the via hole areshown in FIGS. 9 to 13.

[0076] As shown in FIG. 9, the interlayer-insulating film 20 is formedon the entire surface of a layer 40 that is provided directlyunderneath. As shown in FIG. 10, a self-organizing film 41 is formed onthe interlayer-insulating film 20. The self-organizing film 41 is anorganic monomolecular film including a water-repellent fluoroalkyl groupon the surface thereof. When the self-organizing film 41 is irradiatedwith ultraviolet light through a photomask 42, as shown in FIG. 11, onlythe parts that are irradiated by ultraviolet light are removed, wherebya self-organizing film pattern 43 is formed and theinterlayer-insulating film 20 is exposed, as shown in FIG. 12. When theinterlayer-insulating film 20 is formed with soluble polymers such asPVA, parts of the interlayer-insulating film 20 are dissolved andremoved by being dipped in a desired solvent, whereby a pattern 44 ofthe interlayer-insulating film is formed, as shown in FIG. 13. In thisembodiment, pure water is used to dissolve and remove the parts of thePVA. After the parts of the PVA are removed, the entire surface of thesubstrate is irradiated with ultraviolet light, whereby theself-organizing film that is left on the surface of the substrate isdecomposed and removed, although this is not shown in the figure. As thecircular self-organizing film pattern 43 is removed by using ultravioletlight, the via hole is formed in the interlayer-insulating film. The viahole may be formed in other ways, such as etching using photolithographyor discharging a solvent that is capable of dissolving theinterlayer-insulating film using an I/J method.

[0077] When the via hole is formed, the interlayer wiring 22 a is formedby applying a liquid-gold-material-in-toluene solution inside the viahole using an I/J method, as shown in FIG. 14.

[0078] Next, the source 30 and the drain 31 are formed as shown in FIG.15. As shown in the figure, the source 30 and the drain 31 have bentparts facing each other at a predetermined spacing. That is to say, thesource 30 is comb-shaped, as it has projecting parts 30 a to 30 d.Likewise, the drain 31 is comb-shaped, as it has projecting parts 31 ato 31 d. The projecting parts 30 a to 30 d of the source 30 and theprojecting parts 31 a to 31 d of the drain 31 are alternately aligned,as if the comb-shaped parts are meshed. Accordingly, the comb-shapedparts of the source 30 and the comb-shaped parts of the drain 31 areformed facing each other at a predetermined spacing.

[0079] The drain 31 is formed so as to connect with the cathode layer.The source 30 and the drain 31 may be formed using materials such asmetal or a conductive polymeric material. The source 30 and the drain 31may be patterned by an I/J method. In this embodiment, aliquid-gold-material-in-toluene solution is applied by an I/J method.The gold film obtained in that manner is about 50 nm thick.

[0080] The organic-semiconductor layer 32 is formed as shown in FIG. 16.The organic-semiconductor layer 32 may be made of organic materials, byspin coating, vapor deposition, an I/J method, and so forth. In thisembodiment, an organic-semiconductor film made of anthracene is formedby spin coating a liquid material in which anthracene is dissolved in axylene solvent. The thickness of the organic-semiconductor film is 200nm. Other organic-semiconductor materials, such as tetracene orpentacene may be used.

[0081] Then, the gate-insulating film 34 is formed as shown in FIG. 17.For the gate-insulating film 34, the same materials as those for theinterlayer-insulating film may be used. In this embodiment, a PVA filmis used, and the PVA film is formed to a thickness of 1 μM by spincoating.

[0082] The gate line 33 is formed so as to cover the bent parts of thesource 30 and the drain 31, as shown in FIG. 17. That is to say, thegate line 33 covers the bent parts of the source 30 and the drain 31,which face each other at a predetermined spacing. Hence, the width ofthe gate becomes longer. The gate line 33 is formed by using aliquid-gold-material-in-toluene solution, as in the case of the source30 and the drain 31. As the solvent for the liquid-gold material,toluene is used, and the metal film obtained has a thickness of about 50nm.

[0083] After the interlayer-insulating film 20 a is formed, a via hole21 b is formed in the above-described manner, as shown in FIG. 18. Thistime, however, a part of the PVA film is dissolved and removed with purewater, and a part of the organic-semiconductor layer is dissolved andremoved by xylene, for electrically connecting a source line and thesource 30.

[0084] Finally, the source line 35 is formed as shown in FIG. 19. Thesource line 35 is formed with the interlayer wiring 22 b, so as toconnect with the source 30. A liquid-gold-material-in-toluene solutionis used as the material, as in the case of the source 30 and the drain31, and an I/J method is used for forming the source line. The thicknessof the obtained gold film is about 50 nm. Thus, the basic processes arecompleted. Further, a protecting film or the like may be formed on thesource line 35.

[0085] In the organic electroluminescent device which is formed asdescribed above, the source 30, the drain 31 and the gate line 33 form athin-film transistor.

[0086] Next, the steps of manufacturing the organic electroluminescentdevice according the second embodiment of the present invention will nowbe described. FIGS. 20 to 28 show the steps of manufacturing the organicelectroluminescent device. In FIGS. 20 to 28, parts (a) are plan views,and parts (b) are sectional views through portions A-A shown in theparts (a).

[0087] First, the source line 35 is formed on the substrate 10, as shownin FIG. 20. The source line 35 is formed, using aliquid-gold-material-in-toluene solution, by an I/J method. Thethickness of the gold film obtained is about 50 nm. Then, theinterlayer-insulating film 20 is formed. Using a PVA film, theinterlayer insulating film 20 is formed to a thickness of 1 μm by an I/Jmethod. The PVA film is formed in such a manner that no PVA film isformed at an area above the source line 35. The via hole 21 b is formedin the interlayer-insulating film 20 as described above.

[0088] The gate line 33 is formed as shown in FIG. 21. Using aliquid-gold-material-in-toluene solution, the gate line 33 is formedusing an I/J method. The thickness of the gold film obtained is about 50nm. Then, the gate-insulating film 34 is formed. For the gate-insulatingfilm 34, a PVA film is formed to a thickness of 1 μm using an I/Jmethod. The PVA film is formed in such a manner that no PVA film isformed at an area above the source line 35.

[0089] The organic-semiconductor layer 32 is formed as shown in FIG. 22.The organic-semiconductor material used for the organic-semiconductorlayer 32 is the same as that used in the above-described firstembodiment. The organic-semiconductor layer 32 is formed to a thicknessof 200 nm in thickness using an I/J method. An organic-semiconductivefilm is formed in such a manner that no organic-semiconductive film isformed at an area above the source line.

[0090] Next, by applying a liquid-gold-material-in-toluene solutionusing an I/J method, the interlayer wiring 22 b is formed as shown inFIG. 23. After that, the source 30 and the drain 31 are formed as shownin FIG. 24.

[0091] In that case, as shown in this figure, the source 30 and thedrain 31 have the bent parts which face each other at a predeterminedspacing. That is to say, the source 30 has projecting parts 30 a to 30d, and is formed in a comb-shape. Likewise, the drain 31 has projectingparts 31 a to 31 d, and is formed in a comb-shape. The projecting parts30 a to 30 d of the source 30 and the projecting parts 31 a to 31 d ofthe drain 31 are alternately aligned, so that the comb-shaped parts aremeshed. Accordingly, the comb-shaped parts of the source 30 and thecomb-shaped parts of the drain 31 are formed facing each other at apredetermined spacing. Accordingly, as the gate line 33 covers the bentparts of the source 30 and the drain 31, the width of the gate becomeslonger.

[0092] The source 30 is formed so as to connect with the source line 35.In this embodiment, a liquid-gold material is applied using an I/Jmethod. Ethanol is used as the solvent of the liquid-gold material. Thethickness of the gold film obtained is about 50 nm.

[0093] Then, the interlayer-insulating film 20 a is formed as shown inFIG. 25. Using a PVA film, the interlayer-insulating film 20 a is formedto a thickness of 1 μm using an I/J method. The PVA film is formed insuch a manner that no PVA film is formed at an area above the drain 31.The via hole 21 a is formed in the interlayer-insulating film 20 a asdescribed above.

[0094] Further, the interlayer wiring 22 a is formed as shown in FIG.26. In this embodiment, a liquid-gold-material-in-toluene solution isapplied using an I/J method. Then, as shown in the figure, the cathodepattern 14 is formed so as to connect with the drain 31.

[0095] Further, the luminescent layer 13 is formed as shown in FIG. 27.The luminescent layer 13 is formed by spin coating. The material of theluminescent layer 13 is the same as that of the first embodiment.Finally, as shown in FIG. 28, the transparent conductive film 11 isformed on the entire surface using a sputtering method. The thickness ofthe film obtained is 150 nm. The processes are thus completed. Next, atransparent protection film may be formed on the transparent conductivefilm 11.

[0096] In the organic electroluminescent device configured as describedabove, the source 30, the drain 31, and the gate line 33 form theorganic thin-film transistor.

[0097] In the organic electroluminescent device obtained in theabove-described first and second embodiments, the organic-thin-filmtransistor controls the organic electroluminescent element.

[0098] In the above-described first and second embodiments, the sourceand the drain, which form the organic thin-film transistor element, areprovided facing each other at a predetermined spacing, forming acomb-shape. When the source and the drain are provided facing each otherat a predetermined spacing, the width of the gate becomes longer.Therefore, the source and the drain may be formed in a spiral-shape, notin a comb-shape, facing each other at a predetermined spacing. When thesource and the drain are formed in a spiral-shape, the spiral-shapedsource and the spiral-shaped drain that winds in the same direction asthat of the source may be formed at a predetermined spacing. That is tosay, the width of the gate becomes longer when the source and the drainare provided with the bent parts facing each other at a predeterminedspacing. Accordingly, the organic thin-film transistor element issuitable for driving the organic electroluminescent element.

[0099] With reference to the description in the claims, the presentinvention may have the following forms.

[0100] (1) An organic electroluminescent device according to any one ofclaims 1 to 8, further comprising interlayer wiring that electricallyconnects the organic thin-film transistor element with the organicelectroluminescent element.

[0101] (2) A method of manufacturing an electroluminescent deviceaccording to any one of claims 9 to 16, further comprising a step ofproviding interlayer wiring that electrically connects the organicthin-film transistor element with the organic electroluminescentelement.

[0102] Next, examples of the electronic apparatus to which theabove-described organic electroluminescent device is applied will now bedescribed. FIG. 29 is a perspective view showing the configuration of amobile personal computer to which the described organicelectroluminescent device is applied. In this figure, a personalcomputer 1100 includes a main unit 1104 having a keyboard 1102, and adisplay unit 1106. The display unit 1106 includes the described organicelectroluminescent device 100.

[0103]FIG. 30 is a perspective view showing the configuration of amobile phone to which the above-described organic electroluminescentdevice 100 is applied to the display unit thereof. In this figure, amobile phone 1200 includes a plurality of operating buttons 1202, areception port 1204, a transmission port 1206, and the above-describedorganic electroluminescent device 100.

[0104]FIG. 31 is a perspective view showing the configuration of adigital still camera in which the described organic electroluminescentdevice 100 is applied to the finder thereof. Also, the figure brieflyshows the connection with external devices. In an ordinary camera, afilm senses light from an optical image of a subject. On the contrary,the digital still camera 1300 generates an image-pickup signal byopto-electronically converting the optical image of the subject using animage-pickup device such as a CCD (Charge Coupled Device). The describedorganic electroluminescent device 100 is provided in the back of a case1302 of the digital still camera 1300, for providing display based on animage-pickup signal provided by the CCD. The organic electroluminescentdevice 100 functions as the finder for displaying the subject. Alight-receiving unit 1304 that includes an optical lens and the CCD isprovided at the viewing side (the rear side in the figure) of the case1302.

[0105] When a photographer confirms a subject image that is displayed onthe organic electroluminescent device 100, and presses a shutter button1306, the image-pickup signal provided by the CCD at that very time istransferred and stored in a memory on a circuit board 1308. In thedigital still camera 1300, a video-signal output terminal 1312 and aninput-output terminal 1314 for data communication are provided on theside of the case 1302. As shown in the figure, a television monitor 1430is connected to the video-signal output terminal 1312, and a personalcomputer 1430 is connected to the input-output terminal 1314, as theneed arises. Further, the image-pickup signal, which is stored in thememory on the circuit board 1308 by a predetermined operation, is outputto the television monitor 1430 and the personal computer 1440.

[0106] The electronic apparatus to which the organic electroluminescentdevice 100 of the present invention is applied includes a television, aviewfinder-type video tape recorder, a monitor-direct-view-typevideo-tape recorder, a car navigation system, a pager, an electronicpersonal organizer, an electronic calculator, a word processor, aworkstation, a video phone, a POS terminal, and a device having a touchpanel, in addition to the personal computer in FIG. 29, the mobile phonein FIG. 30, and the digital still camera in FIG. 31. Of course, thedescribed organic electroluminescent device 100 may be applied to theabove-described electronic apparatus as the display unit thereof.

[0107] The organic thin-film transistor is mechanically flexible, andmay be made by a liquid-phase process. Because of these advantages, theorganic thin-film transistor may be used for a sheet display that isformed on, for example, a plastic substrate, a paperlike substrate, andso forth.

Advantages

[0108] As has been described in the present invention, the organicthin-film transistor is adopted for driving the organicelectroluminescent element. Subsequently, no special devices arerequired, and the entire manufacturing operation may be performed byinkjet processes. Accordingly, the manufacturing cost is reduced.Further, for one pixel, the size of the organic thin-film transistorelement is arranged to be larger than that of the organicelectroluminescent element. The source and the drain, which form thethin-film transistor element, are configured to have bent parts facingeach other at a predetermined spacing. By providing the gate coveringthe bent parts of the source and the drain, the width of the gatebecomes longer. Accordingly, the organic thin-film transistor element issuitable for driving the organic electroluminescent element.

1. An organic electroluminescent device comprising: an organic thin-filmtransistor element including at least an active layer made of an organicmaterial; and an organic electroluminescent element driven by theorganic thin-film transistor element.
 2. The organic electroluminescentdevice according to claim 1, further comprising a substrate, wherein theorganic electroluminescent element is provided between the substrate andthe organic thin-film transistor element.
 3. The organicelectroluminescent device according to claim 1, further comprising asubstrate, wherein the organic thin-film transistor element is providedbetween the substrate and the organic electroluminescent element.
 4. Theorganic electroluminescent device according to any one of claims 1 to 3,wherein, in each pixel, the total area of the area of a source regionand the area of a drain region of the organic thin-film transistorelement is larger than the area of a region provided with a luminescentmaterial of the organic electroluminescent element.
 5. The organicelectroluminescent device according to any one of claims 1 to 4, whereinthe source and the drain, which constitute the organic thin-filmtransistor element, have bent parts that face each other at apredetermined spacing.
 6. The organic electroluminescent deviceaccording to claim 5, wherein a gate is provided so as to cover the bentparts of the source and the drain.
 7. The organic electroluminescentdevice according to claim 5 or claim 6, wherein the bent parts of thesource and the drain are provided in a comb-shape and face each other ata predetermined spacing.
 8. The organic electroluminescent deviceaccording to claim 5 or claim 6, wherein the bent parts of the sourceand the drain are provided in a spiral-shape and face each other at apredetermined spacing.
 9. A method of manufacturing an organicelectroluminescent device, comprising: a step of forming an organicelectroluminescent element above a substrate; and a step of forming anorganic thin-film transistor element, for driving the organicelectroluminescent element, above the organic electroluminescentelement.
 10. A method of manufacturing an organic electroluminescentdevice, comprising: a step of forming an organic thin-film transistorelement above a substrate; and a step of forming an organicelectroluminescent element, which is driven by the organic thin-filmtransistor element and performs predetermined display, above the organicthin-film transistor element.
 11. The method of manufacturing an organicelectroluminescent device according to claim 9 or claim 10, wherein, ineach pixel, the total area of the area of a source region and the areaof a drain region of the organic thin-film transistor element is largerthan the area of a region provided with a luminescent material.
 12. Themethod of manufacturing an organic electroluminescent device accordingto any one of claims 9 to 11, wherein the source and the drain, whichconstitute the organic thin-film transistor element, have bent partsthat face each other at a predetermined spacing.
 13. The method ofmanufacturing an organic electroluminescent device according to claim12, wherein a gate is provided so as to cover the bent parts of thesource and the drain.
 14. The method of manufacturing an organicelectroluminescent device, according to claim 12 or claim 13, whereinthe bent parts of the source and the drain are provided in a comb-shapeand face each other at a predetermined spacing.
 15. The method ofmanufacturing an organic electroluminescent device, according to claim12 or claim 13, wherein the bent parts of the source and the drain areprovided in a spiral-shape and face each other at a predeterminedspacing.
 16. The method of manufacturing an organic electroluminescentdevice, according to any one of claims 9 to 15, wherein, at least theorganic thin-film transistor and an organic-luminescent layer of theorganic electroluminescent element are formed by a liquid-phase process.17. An electronic apparatus comprising an electroluminescent deviceaccording to any one of claims 1 to 8.